The present invention relates to motion picture production in general and to motion pictures that utilize virtual sets in particular.
The cost of producing today""s motion pictures, particularly action adventure, science fiction and fantasy films that utilize substantial digital visual effects, is increasing astronomically. Large scale productions, such as the movie Titanic, are high risk ventures, with escalating costs increasingly difficult to contain. Studios have responded to these economic realities by cutting the number of films they produce, canceling projects and moving production out of the country.
Digital technologies, and in particular computer generated imaging and Chromakey techniques to create special visual effects, have undoubtedly enhanced the creative potential of motion picture production. Digital visual effects, however, have generally been used in conjunction with conventional large scale production methods that involve major stars, large crews, exotic location shooting, lengthy shooting schedules and spectacular physical sets, and have tended to increase rather than decrease the cost of motion picture production.
What has been lacking is a comprehensive approach to incorporating digital technology into all phases of the motion picture production process to accelerate the pace of production and significantly decrease costs by reducing the downtime associated with set and lighting changes; by filming actors on a sound stage using photorealistic backgrounds of virtual worlds and characters in place of real environments and sets; and by providing immediate on-line editing capability both prior to and during the production process.
The present invention is directed to a method and apparatus for significantly reducing the cost of motion picture production. xe2x80x98Motion picturexe2x80x99 as used herein includes films, TV shows, IMAX 3D experiences, simulator rides, interactive games and the like.
In accordance with the present invention, motion pictures are produced on a sound stage using live actors, limited foreground sets and virtual background sets of computer generated images. Live action is filmed using Chromakey techniques, in which actors are filmed on a sound stage in front of a background of uniform color, usually blue or green. A keying unit detects those parts of the camera image that contain the xe2x80x9ckeyxe2x80x9d color, and replaces them with the background virtual set of computer generated images.
During filming, the virtual background sets are instantaneously composited with the live foreground action, to create a real-time xe2x80x9creferencexe2x80x9d composite which can be seen in a camera viewfinder, on monitors around the stage, and in a screen room, to facilitate fast and intuitive alignment of live action foreground with the virtual background and to allow various locations, compositions, scenes, and complex camera moves to be explored in real-time in a virtual environment. The xe2x80x9creferencexe2x80x9d composite is immediately available to a non-linear editor for editing both prior to and during principal photography.
The present invention includes a method and apparatus for producing a composite motion picture image on a stage using live images of characters and set components combined with computer generated images. The method includes generating a database of computer generated image element signals indicative of computer generated images, each image having a plurality of computer image elements, with a pre-established geometric position relative to one another. A database of computer image element position signals correlating the position of each of the image elements in a stage geometry is also generated. Character and set image element signals indicative of live character and set component images within the stage geometry is recorded, wherein each image has a plurality of character and set image elements. Simultaneously with the live character and set image element signals, character and set position signals which associate a character or set component position with a corresponding position in the stage geometry is also recorded. The method also includes generating recording apparatus position signals indicative of the position of a recording apparatus in the stage geometry and optical field signals indicative of the optical field of view of the recording apparatus for the live character and set component images. Optical parameter signals corresponding to the optical parameters of the recording apparatus are also recorded. The computer image element position signals are then modified in dependence on values of the recording apparatus position signals, optical parameter signals and optical field signals. Additionally, select ones of the character and set image element signals are identified to be replaced by select ones of the computer generated image element signals in dependence on the computer image element position signals and the character and set position signals. Further, the identified character and set image element signals are substituted with corresponding ones of the computer generated image element signals to form a set of initial composite image signals. The method than generates, in substantially real time, an initial composite image of the live character and set component images and the computer generated images from the initial composite image signals. The initial composite image is presented, in substantially real time, to a display associated with the recording apparatus.
This present method and apparatus substantially reduces the need to create expensive, large-scale physical sets and dramatically accelerates the shooting process by reducing the size of crews and the hours spent rigging, lighting and operating each set or location.
It is an objective of the present invention to simplify live action shooting, making it possible to greatly increase the number of set-ups per day.
It is a further objective to improve image quality and reduce lighting requirements by using an all-digital camera, thereby eliminating film handling, loading, processing, printing, projecting and scanning costs and delays.
It is still a further objective to dramatically reduce the cost of producing visual effects feature films through reduced set and crew costs and powerful photorealistic computer graphics imagery.
It is yet a further objective to simplify editing of scenes, sequences or an entire film using xe2x80x9creferencexe2x80x9d composites.
These and other objectives and advantages will become more readily apparent in light of the following description and associated drawings.